The present invention relates generally to apparatus for obtaining a wide field of view at a first location without the use of moving parts, and for selecting a portion or portions of that view under selected viewing parameters at a second location without the transmission of control signals from the second location to the first location. Further, the invention relates to the transformation of the selected view into a correct perspective for human viewing at the second location.
The fundamental apparatus, algorithm and method for achieving perspectively-corrected views of any selected portion of a hemispherical (or other wide angle) field of view are described in detail in the above-cited U.S. Pat. No. 5,185,667. This patent is incorporated herein by reference for its teachings. Through the use of this technology no moving parts are required for achieving pan, tilt and rotation xe2x80x9cmotionsxe2x80x9d, as well as magnification. Briefly, a wide angle field of view image is captured into an electronic memory buffer. A selected portion of the captured image containing a region of interest is transformed into a perspective correct image by an image processing computer. This provides direct mapping of the wide angle image region of interest into a corrected image using an orthogonal set of transformation algorithms. The viewing orientation, and other viewing perimeters, are designated by a command signal generated by either a human operator or a form of computerized input. The transformed image is deposited in a second electronic memory buffer where it is then manipulated to produce the output image as requested by the command signal.
The invention of that patent was envisioned as being primarily a unitary system in that all components were located in close proximity. Even in the subsequent patent applications (Ser. No. 08/014,508, above-cited, and Ser. No. 08/068,776, filed Jun. 1, 1993) of related technology, the inventions were envisioned as having all components in close proximity. As such, there could be ready verification of operation, alignment and any needed adjustment.
There are applications, however, for the same type of omniviewing of wide angle images where there is a substantial distance between where the initial image occurs and the location where the perspectively-corrected views are to be utilized. For example, in the teleconferencing art some type of display is exhibited at one location, and persons at a distant location desire to view all or a selected portion of the display. According to common practice prior to the development of the basic system for providing a selected image without the use of moving components, control signals had to be sent to the site of the display so as to make necessary adjustments to equipment at that site so as to select a portion of the display, or enhance a selected portion, for use of the view at the distant location. Further, it is often desirable to have a plurality of viewers each individually wishing to observe selected portions of the image, with those plurality of viewers potentially scattered at separate viewing locations. The prior art for this situation would require a plurality of cameras (video sources) and a plurality of control signals being sent to the site of the images, and each viewer taking a selected time for their individual viewing.
Accordingly, it is an object of the present invention to utilize variations on the technology of production of perspective-corrected views, at one or more locations, of at least portions of an overall image occurring at a distant location.
It is another object of the present invention to provide for the generation of a wide angle image at one location and for the transmission of a signal corresponding to that image to another location, with the received transmission being processed so as to provide a perspective-corrected view of any selected portion of that image at the other location.
It is also an object of the present invention is to provide for the generation of a wide angle image at one location and for the transmission of a signal corresponding to that image to another location, with the received transmission being processed so as to provide at a plurality of stations a perspective-corrected view of any selected portion of that image, with each station selecting a desired perspective-corrected view.
A further object of the present invention is to provide for the generation of a wide angle image at one location and for the transmission of a signal corresponding to that image to a plurality of other locations, with the received transmission at each location being processed so as to provide a perspective-corrected view of any selected portion of that image, with the selected portion being selected at each of the plurality of other locations.
These and other objects of the present invention will become apparent upon a consideration of the drawings referred to hereinafter, and the detailed description thereof.
In accordance with the present invention, there is provided a video camera at a first location, with that camera having a wide field of view lens, such as a fish-eye lens, to produce an electrical signal corresponding to the image as seen through the lens. This electrical signal, which is distorted because of the curvature of the lens, is inputted to apparatus for the transmission of the electrical signal to a remote location. The transmission can be by wire or wireless depending upon the circumstances. If by telephone wire, the apparatus for transmission includes a xe2x80x9ccompressionxe2x80x9d portion due to the lower band width of these lines. If transmission is to be wireless, appropriate broadcasting apparatus is included.
At each location where viewing is desired, there is apparatus for receiving the transmitted signal. In the case of the telephone line transmission, xe2x80x9cdecompressionxe2x80x9d apparatus is included as a portion of the receiver. The received signal is then digitized. A selected portion of the digitized signal, as selected by operator commands, is transformed using the algorithms of the above-cited U.S. Pat. No. 5,185,667 into a perspective-corrected view corresponding to that selected portion. This selection by operator commands includes options of angles of pan, tilt, and rotation, as well as degrees of magnification.
The system provides for alternate types of receiving command signals. For example, there can be a plurality of stations for inputting of these command signals to a single transform unit. Further, there can be the inputting of command signals at each of several receiving stations, each of these receiving stations including a transform unit.